







” — 
cc 
ul a 
Lu 
= bE 
= Lu 
o 1978 Cc 2 1978 D 
a wl b 10-4 29 
31 - Q 9 , 27 ry 
2.04 wer 84 
za 27 “vi 13 ‘ bk 7 13 
Gy 4s a ef ol 
Ee | oO 5 
C) 1.04 B hy 4 Lu 44 
— me 34 
= 0.54 ” 24 
{— 
“) z | 
Se < 
O =i 
J OW 
<q x 13 
5 Ml 7 
W) << S 7 26 1979 F 
> “ 10 22 26 7 
a 29 
= 8 
<< i 
LW 7 
S 6 
9 1 
4 ‘ 
3 
2 
1 
2 3 4 5 6 7 8 9 10 

AGE OF COVER (YEARS) 
Fig. 4. Visual obstruction and height measurements + one standard deviation, mean, and range per age class of residual seeded nesting 
cover during spring, 1977-79, Sample size appears above the range lines. 
greater in visual obstruction and plant height than did significant for 58 stands in 1977 (r = 0.74), 119 stands in 
stands dominated by other wheatgrasses (Table 1). 1978 (r = 0.52), and for 128 stands in 1979 (r = 0.65). 
Repeated measures analysis of covariance indicated that 
visual obstruction measurements were not significantly in- 
Correlation coefficients for the relation between height fluenced by the soil capability class or by the age class 
measurements and visual obstruction measurements were (Table 2), However, the covariates, percent grass and 
Age, Soils, Precipitation, and Percent Grass 
